This is an undated file photo of the electric chair at the Tennessee State prison in Nashville. / AP

by Chas Sisk, The Tennessean

by Chas Sisk, The Tennessean

NASHVILLE, Tenn. -- A law signed by Gov. Bill Haslam to remove roadblocks to executions in Tennessee by expanding use of the electric chair could instead create new legal hurdles, experts on the death penalty said Friday.

The measure that would allow electrocutions if lethal injection is found unconstitutional or the drugs are not available is essentially a backup plan for the state. But it's likely to spur new court challenges on behalf of the condemned.

Those cases mean it could be months or even years before Tennessee starts using the electric chair again - if it ever does at all.

"Of course death penalty opponents will challenge it," said Michael Rushford, president and chief executive of the California-based Criminal Justice Legal Fund, which supports the death penalty.

The law, which Haslam signed Thursday and which goes into effect July 1, comes amid a national debate over the procedures, effectiveness and humaneness of lethal injection. Many suppliers of lethal injection drugs, particularly those based in Europe, have refused to sell states the chemicals most often used in executions.

Tennessee officials have struggled to procure the drugs, and the state has not executed an inmate since 2009.

Other states have responded by turning to untested drug combinations or less reliable makers, an approach that has created problems of its own. In January, the Ohio execution of Dennis McGuire by lethal injection took 25 minutes. Then last month, Oklahoma officials halted the execution of Clayton Lockett because injections had not been administered correctly. He died less than an hour later of heart failure.

Oklahoma immediately delayed a second execution so it could review its lethal injection protocols. On Tuesday, U.S. Supreme Court Justice Samuel Alito halted an execution in Missouri after attorneys questioned whether the inmate would suffer similarly on the gurney.

Only eight states permit electrocution, and the method has been used sparingly. But it appears to be on firmer legal footing, at least for the time being. The U.S. Supreme Court repeatedly has upheld the constitutionality of the electric chair, experts said.

But there may be some room for legal debate. The Supreme Court also has endorsed the notion that the Eighth Amendment's ban on "cruel and unusual punishment" can evolve with social norms.

That rationale played into a 2008 decision by the Nebraska Supreme Court, which also bans cruel and unusual punishment, to strike down electrocution. Tennessee has a similar clause in its constitution.

"Challenges will be made, and there will be judges that say it's going to be cruel and unusual," Rushford said. "But it would have to go all the way to the Supreme Court to overturn it (electrocution), which is a long process."

Attorney General Robert Cooper predicted those challenges in an opinion released in March. He said the state should be able to defend electrocution successfully.

But David Raybin, a defense attorney who helped write the state's death penalty law in 1977, said Tennessee's electric chair measure presents a second legal problem. Inmates who already have been condemned can argue they should not be put to death with a method that was not in use when they committed their crimes.

Tennessee lawmakers tried to head off that same attack on the state's death penalty in 1998, when they amended the law to add lethal injection. They gave inmates who committed crimes before Jan. 1, 1999, the option of the electric chair or lethal injection.

"It would have been unconstitutional to change the method," Raybin said.

Rushford said the state has a good defense this time around, in that it never completely discontinued use of the electric chair. Attorneys will almost certainly get the chance to argue the question in the coming months.